JSF 1.2 managed bean how to get the getter value

Question

I new to Java and JSf, am getting null pointer error when accessing a getter value from backing bean in controller. Here is the code snippet :

JSP; input text area and am able see the sysout in setter the value submitted from page and not able to access the getter values. faces-config.xml

<managed-bean>
        <managed-bean-name>researchHisttoryController</managed-bean-name>
        <managed-bean-class>com.controller.ResearchHisttoryController</managed-bean-class>
        <managed-bean-scope>session</managed-bean-scope>
        <managed-property>
            <property-name>history</property-name>
            <property-class>com.researchhistory.model.ShipmentHistory</property-class>
            <value>#{history}</value>
        </managed-property>
    </managed-bean>
    <managed-bean>
Controller class:

private ShipmentHistory history;

//getters and setter followed;

am accessing varaible from ShipmentHistory class as getHistory.getTrackNumber; NPE error

ShipmentHistory.java
private String trackNumber;
//getters and setters

can please help me out where am doing wrong. Thanks for your time.

can you give your jsf page code and backing bean code that how to set a value from input text — Jman
<h:inputTextarea id="trackingNumber" binding="#{researchBackingBean.trackingNumber}" validator="#{researchBackingBean.processesValidate}" value="#{shipmentHistory.trackingNumbers}" /> — userJ
BackingBean validation: private HtmlInputTextarea trackingNumber; let me know if this good enough. — userJ

BalusC BalusC · Accepted Answer · 2012-02-08T00:55:48

Then #{history} is just null. Apparently you haven't declared it as a managed bean.

<managed-bean>
    <managed-bean-name>history</managed-bean-name>
    <managed-bean-class>com.researchhistory.model.ShipmentHistory</managed-bean-class>
    <managed-bean-scope>session</managed-bean-scope>
</managed-bean>

But this is kind of odd. A model should not be treated as a controller. Depending on the functional requirement, there must surely be better ways. Perhaps you just want a new blank instance of ShipmentHistory everytime when the ResearchHisttoryController get created. In that case, do the job in the (post)constructor of the backing bean instead.

public ResearchHisttoryController() {
    history = new History();
}

(please note that you've a typo in the backing bean class name)

JSF 1.2 managed bean how to get the getter value

1 Answers